Hobbing machine



H. R. HAWGOOD HOBBING MACHINE Filed May 14, 1932 July 2i, 1936e w 1034 7 54 444.3 w M 4 4 4 d 9 3 3 5 .I ||1 um Z7 33 1liA 4the' ibase.

Patented July 21, 1936 UNITED STATES 2,048,503 1 HoBING MACHINE Harvey R. Hawgood, Cleveland, Ohio, assigner to 'The Lees-Bradner Company, Cleveland, Ohio, aV corporation of Ohio Application May 14, 1932, Serial No. 611,396

6 Claims.

This invention relates to a machine for hobbing gears and the like, and more particularly to amachine by which helical teeth, threads, and other curved and inclined surfaces may be lformed.

An object of the invention is to provide an improved machine which will accurately' produce helical gear teeth and the like.

Another object is to provide an improved ma- .chine which will automatically compensate for .any desired helix angle about which the teeth of agear are to be formed;

Another object is to provide an improved ma'- 'chine which ywill be eicient in operation and sim- .ple in construction.

, ,bodying the invention, the left hand half being shown in section, taken on the line I-I of Figure 2; and

Figure 2 is a perspective view of the two cam devices which actuate the mechanism of Figure 1.

The machine shown comprises a base I provid- :ed with a centrally disposed'upwardly extending pedestal 2 upon which is pivoted a main vframe 3 by which the bulk of vthemechanism is supported A pulley 4, driven from any suitable source-of power, drives a horizontal shaft 5 jour- -nalled in the base and provided on its inner end with a bevelled gear 6 meshing with a bevelled gear "I, upon a vertical shaft 8, also journalled in The upper end of this shaft 8 is provided with a pinion 9, which meshes with a ring gear I 0 rigidly attached to the frame 3, and by this means rotates the frame about the pedestal.

A plurality of similar hobbing mechanisms are mounted on the frameand travel with it about the pedestal, the arrangement being similar in general to that shown in the patent to Homer C. Warner, Number 1,836,210, issued December 15, 1931.

Each hobbing mechanism consists of a tool spindle Il mounted in horizontal bearings carried by a carriage I2, slidable radially of the frame, on horizontal ways I3. Each tool carriage is provided with an inwardly extending 'arm I4 provided on its inner end with a roller I5 .the side of the frame.

which runs in a cam-shaped groove in a sleeve I6 rigidlyattached to the pedestal, the shape, of

thecams. being better shown in Figure 2. i A The toolspindle is rotated by means of gears Il driven by a bevelled gear I8 carried upon a vii radial shaft IB which is splined toga bevelled :gear carried within'ithe frame, and 1 driven by abevelled gear ZI on. the lower end of a vertical shaft 22 journalled in theframe.Y

. The shaft 22 is driven at its upper end by l0 gears 23 and 24, the latter of which iskeyed to a vertical shaft 25 having at its upper end `a bevelled gear 26 meshing with a bevelled gear 2l upon a horizontal shaft 28`provided at its outer end with a gear 29 and driven by the gear 3,0 I5

Voperated* by, the `shaft of an electric motor 3|. `The motor 3| is mounted upon the `topof the frame, and gears 24 and 3.0 may be connected pto each hobbing unit, theA power beingv transmitted .to the several gears 24 by idlers in ,the part 2 0 of the frame.

A vertical work spindle 32 is Supported by f carriage 33 slidable upon vertical Ways ,'34Y on The work carriage is provided at its lowerend with a roller 35 running ,25 upon a circular cam-shaped track 3,6 and so praises .and lowers the carriage ,as the frame travels aroundthe pedestal. 1

The work spindle has keyed to it, within the carriage, a bevelled gear 3l driven by another bevelled gear'38 which is keyed lto :a radially extending shaft 39. This shaft is journalled within an inward extension 4,0of the carriage and is provided at its inner end with a bevelled gearl 4I meshing with a bevelled gear 42, also journalled in the extension 40.

The bevelled gear 42 is splined to alvertically extending shaft 43, provided with a helical spline, and journalled at its lower end-within the frame 3 and at its .upper end in a bracket 44 rigidly attached to the frame. Y

The upper end of shaft 43 is provided with a pinion 45 which, through Vback gears 46., supported by the frame, is driven by va pinionA'I carried on the lower end Vof a shaft V48, also journalled in the frame. The upper end of shaft 48 has keyed to it a bevelled gear 49 meshing with gear 2U above referred to.

It will, therefore, be seenv that if the carriage 33 be held in stationary position when motor 3I is operated, this motor will drive, through the gearing described, both the cutter spindle and work spindle, these two rotating at predetermined relative speeds and that these speeds may be adjusted by proper selection of gears 45, 46 and 4lV Y Y Y 1 '72,048,503

' or'rof change gears anywhere in the gearY train between the spindles.

n is moved up or downupon the ways 34, gear 42 '-{will be rotated by its engagement with the helical spline ,in Shaft 43, varying the relativeY rotation This spline Yis chosen to rotatethe spindles relative each other of the work and tool spindles.

' anV amount corresponding to the desired helix angle of alhelical gear which Yis to lbe cut, thework Ygear supported on spindle!!! being given, for each V,incrementof axial movement, a corresponding increment of rotational movement relative theV Vcutter Vor hob.V This increment'dependssoielyi uponitheV movement of the carriage, .sothat any irregularities in the'feed willnot eiectithe' proper cutting `of the helix angle upon the work blank. Y. Obviously, an elongated helical gear could, be substituted for the spline shaft,.this gearfmeshing with a gear driving the work spindle, V and i nt'his respect the spline shaft is an equivalent of such arhelical gear. l

Y il: Also obviouslyV the spline shaft may. b e'inter- .course would be provided as'des'i'r'ed inA practice'` "posed at any place between the spindles. It may, #as shown, be held stationary whilethe spindle 'carryingelement engaging it isvrnoved axially Yrelative it, forfthe spline shaft itselflmight be securedftol the'moving part and causedtok move through agear held against axial displacement toi impart rotation .theretofV Similar arrangements 'could be'made with a vlielical'gear such as just mentionedj'YV C i' TheV usual means Vfor Yadjustingrthe spindlesY axially,lateral ly and angularly, for changing the gear ratios, forsupporting l.the uppergend ofY the work"spindle,`etc., have not `been illustrated, butV of and are now wellleno'ugh understood that' their description is believed unnecessary.: i

' In op'eration,the roller I 5 is moved outwardly by partA of camf I6 and Vmaintained in its Efed position by part B inthis cam. YWhile the cutter fis being held in thispositfion, the work gear or blank is fed upwardlypast it by roller 35 traversing' theupwardslope Cof cam 36. When the J at Yro'ughing cut hasbeenY finished, portion -D of cam l`l6 retracts the cutter, and atlthe same time roller x35 Vpasses'onto the ldownward lslope E permitting theV work carriageto drop back` toits lowermost position. Thecutter Vis then fedinby the motion of its roller along' portion F'fV amV I6. for thenishing cut,*and 'the workY carriage again" fed upfwardly by roller 35 traversing upwardly inclined portion G of cam 3 6. VfAt the end of the finishing cut, the `tool'is retractedby portion H of its 'cam turnthe parts to their :original positinsf YYYWhile I have described the illustratedembod'i- `rne'ntof my invention inY some particularity, this v -is done by way of illustrationV only, itjbeingV ob.-

Vviousi that many other lembodiments will readily occur'to thoseskilled-in lthisv art, andI do not,

. Ltherelo're,limit"'myself kto the precise details shown; and described, :but claim asimy inventionV Vall.- embodimentsjvariations and modifications Ycoming within the 'scope ofthe subjoined claims.

If, however,V the carriageV and roller 35 descends incline I/ ofcam 36 to re- 1. A hobbing machine comprising a work spindle and a tool spindle, means for imparting a, rela'- tive motion to `said spindles axially and radially of the workspindle respectively, a gear train connesting said spindles having a single definite gear ratio'and including two elements, one drivingthe otherV throughhelicall engaging` surfaces, one 'ofV said elements being movable axially Vre'laa .tivej the other uponV axial movement of the spindles kwhereby an increment of rotation'isimparted the spindl'es relative each otherrfor every increment'of -L'relativeaxial movement.

2`. A hobbing machinecomprising a frame, a

Yslide movable thereon, aspindle carried by said Y.`slide,ra spindle carried by said frame, gearing bev tween saidV spindles having a single denite gear ratio including two members. in'driving engagement with each other, one journalled on `the frame and the other journalled on the slide, and having 20 Y 3. A rotaryy hobbing machine comprising albed, a base rotatablejon said bed, a spindle journalled on said1base,a slide movable upon waysupon g5 said base,a'spindle on said slide', gearing between helical engaging surfaces and driving' means .for said spindles.V Y i Y said spindles, each element of said gearing having its axis fixed relative the axes of both spindles having driving engagement therewith, Vthe gear being journalled in the slide andthe shaft being journalled inthe base.

" 4. A hobbing machinecmprisinga worl:V and `and including-a splined shaft having a helical 1 spline, a gear mounted upon said spline shaftand tool spindle, Yone'of .said spindlsbeing *movableY :15.

relative the other in a'direction ofthe axisof-the workspindle, a gearv trainbetweenfsaid spindles having a single definite gear ratio comprising/twoV elements having Ypositively engaging helical, surfaces, one stationary and the otherrno'vable with saidmovable spindle.AV Y

. 5." A .rotary Vhobbing machine comprising a bed,

a base rotatable on said bed, a hobbing vmecha- -nism carried byV saidba'se comprising -a3w`ork spindlezarid a tool spindle, means for imparting arelative-motionA to saidV spindles, axially land radially'of the Work-spindle, respectively, ai gear elements, one drivingthe other throughvhelical engaging surfaces, one'of saidzelements being movable axially lrelativefthe otherzuponaaxial movement of the spindles whereby an increment of rotation is impartedthespindles relative each otherforY every increment of 'relative axialmovement. 11 V 1 VY6. A rotary hobbing machine comprising abed,

nism carried by said base Vcomprising a'work and 'a tool `spindle,-one of saidsrpindles being movable relative the other in a direction of the axis ofthe 1,69

work spindle, agear" train between said spindles Y comprising two -interengaging elementsl having :train'connecting saidfspindles and including twoy Y Va base rotatable VonV said bed, ahobbingmechameshing helical surfaces, one Vstationary and the i othermovable with said movable spindle.

HARVEY'R'. HAWGOOD. 6;5

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